El Capitan is installed on the MacBook, is this correct?
Have you given consideration to using the new Photos application that is standard with EC (this replaces iPhoto)?
If you don't want to try Photos, you need iPhoto 9.6.1. It's the final and ONLY version of iPhoto which can be used with EC.
This might be why the version from iLife '09 won't install.
Without an Apple-installed version of iPhoto on the MacBook, you will have to search for and install iPhoto "outside of the approved Apple channels" if you want to run it.
(I don't believe it's downloadable from the App Store if the App Store doesn't show a previous version of iPhoto as having been already downloaded from Apple.)
Let me assure you that iPhoto 9.6.1 -is- "findable" and "obtainable" if you're adventurous and know where to look...